Contact card is a kind of smart card, the function is same as contact ID card and IC card, but it does not need power, by the receiving antenna from the reader magnetic field induction take power, and work to calculate the data, feedback to the reader.

Contactless payment systems are credit cards and debit cards, key fobs, smart cards, or other devices, including smartphones and other mobile devices, that use radio-frequency identification (RFID) or near field communication (NFC, e.g. Samsung Pay, Apple Pay, Google Pay, Fitbit Pay, Merpay or any bank mobile application that support Contactless) for making secure payments. The embedded chip and antenna enable consumers to wave their card, fob, or handheld device over a reader at the point of sale terminal. Contactless payments are made in close physical proximity, unlike mobile payments which use broad-area cellular or WiFi networks and do not involve close physical proximity.